‘One would expect similar dynamics to apply to same-sex couples. For lesbian couples, this is not a huge problem; all they need is a sperm donor. But male couples need surrogate mothers.’

‘Unless the law of supply and demand is repealed, the answer [where] is: where wombs are cheapest. At the moment, this is India, where surrogate motherhood has become a $2.3 billion industry.’

‘Supporters of same-sex marriage must recognize they face a serious moral dilemma. Cheap wombs might bring gay men the happiness of being the father of a child of their own. But the cost of that happiness is often borne by poor and uneducated women.’

However what the article did not reveal is that Cook is a senior member of the ultra-conservative Opus Dei sect of Catholicism in Australia who opposes same-sex parenting, abortion and contraception.

Cook, who is the celibate head of an Opus Dei residence, told the Age newspaper in 2006, ‘As a young person, I found the idea of living out Christianity very attractive.’

‘I also wanted to be a professional person. I didn't see how the two were compatible, but Opus Dei had a take on it which showed me it was possible.

'I regard Opus Dei as my family. Most of my friends put all their money to the service of their family; I do the same.'

Cook is the owner and editor of a number of bioethics blogs which advance secular arguments for social conservative causes.

Australian Marriage Equality (AME) national campaign director Rodney Croome said there was no credible evidence that legalizing same-sex marriage in Australia would lead more Indian women to enter into commercial surrogacy arrangements.

‘With reforms to Australia's surrogacy and adoption laws allowing more gay men to become fathers here, and with international surrogacy still prohibitively expensive for most gay men, it is very unlikely we'll see a sudden increase in the number of gay Australians traveling to India to have kids.’

‘What is a surprise is that someone like Michael Cook, who is billed as a science writer, bases his contribution to this important debate on hearsay rather than hard empirical evidence.

‘I look forward to Mr Cook's next article about all the heterosexual couples who pay Indian women to have their children and how this is a reason to ban heterosexuals from marrying.’

Commercial surrogacy arrangement have been outlawed in most Australian jurisdictions meaning that parents who entered into such arrangements could face prison time if they returned to Australia with their child.